Pneumatic pump.



No. 668,405. 7 Patented Feb. l9, lam.

V n. L. HOLDEN.

PNEUMATIC PUMP.

(Application filed May 19, 1900.

(No Model.)

; 2A- I I Mr flassm 2 K 5 Daniel h oldem 46 -59 1 J mans DANIEL L. HOLDEN, OF NEW YORK, N. Y.

PNEUMATIC PUMP.

SPECIFICATION forming part of Letters Patent No. 668,405, dated February 19, 1901.

Application filed May 19, 1900. Serial No. 17,208. \No model.)

T all whom it may concern:

Be it known that I, DANIEL L. HOLDEN, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful-Improvements in Pneumatic Pumps, of which the following is a specification.

My invention relates to pneumatic pumps or compressors, and has for its objects, first, the placing of a movable head for the upper end of the pump and which is a piston-valve which yields to pressure and uncovers numerous ports whereby the pressure escapes without passing through the piston-valve;

second, to valves arranged to surround the piston-valve case and close the aforesaid ports after the compressed fluid has passed from the pumpbarrel; third, to a pump-piston made with an exterior annular shell part having means to pack it against the pump-barrel and a central part moving therein connected to the piston-rod and provided with passage-ways whereby the fluid is allowed to pass and prevented from passing, and other novel features which will be further described.

I attain the objects of my invention by the mechanism illustrated in the accompanying drawings, in which Figure 1 is in general a central vertical section, some parts being not in section, showing the parts as when forcing the fluid. Fig.

2 is a half-vertical central section showing the movable parts as in position while the pump cylinder is receiving fluid or being charged. Fig.3isahorizontalsection through the discharge-ports on line :r m, Fig. 2. Fig. 4 is one-half a top view and one-half with the top cover removed. Fig. 5 is a modification of the delivery-ports and the check-valves. Fig. 6 is one-half a lower end view of the pump-piston and a one-half view of the same with the retaining-ring removed.

Similar figures of reference indicate similar parts throughout the views.

The pump-barrel 1 is formed by the cylinder 2, around which is a cooling-space 3, formed by cylinder 4. over cylinder 2. I have not shown the lower parts of these cylinders, as they may be of any suitable construction to suit the purpose for which the pump is to be used. At the upper end of cylinder 2 the barrel is slightly tapered at 5 to part 6, of

larger diameter, and above 6 is a cone-d seat 7, whereon the piston-valve 8 is seated, the i alve being ground to the seat. The piston= valve is formed of a lower flat disk part 9, having a central boss 10 to act as aguide for the spring 11, which surrounds it and which assists the valves own gravity in forcing the valve 8 to its seat 7 after the fluid-pressure from pump-barrel 1 is delivered, and to a position close to the pistons surface when at its extreme upward movement, which is very important,for as ammonia expands one thousand and nine hundred times with the barometer at 30 it will readily be understood that the efficiency of the pump will be greatly impaired should any gas not be expelled or be prevented from returning to the pump-barrel. Projecting upward from part9 at its outer extre mityis ring 12, its outer surface having grooves 13, into which are inserted packing-rings 1 f. As shown in the present construction, the rings 14 are what are termed spring-rings, they being turned larger than the bore they lit, then out and sprung into the grooves, making a close fit to the cylinder and preventing any return passage of fluid between their. outer face and the surface they fit against. Some other form of packing might be used; but I prefer the form shown. The pistonvalve thus made of solid construction and packed upon its circular guiding and bearing surface works freely, while effectually preventing the passage of any fluid by its sides, as well as preventing any passage under it when seated upon the ground-surface 7.

Surrounding valve 8 is a cylinder 15, joined to cylinder 2 or made integral therewith and projecting somewhat above valve 8 and of larger diameter than barrel 1. At the lower part of cylinder 15 and above seat 7 the cylinder is pierced by delivery-ports 16, as seen in Figs. 1, 2, and 3, the ports opening into a chamber 17, surrounding cylinder 15, which has an outlet 18. As a still further precaution to prevent the possibility of any fluid reaching ports 16 after piston-valve 8 is seated, I place check-valves 19 in chamber 17, and their arrangement is best seen in Fig. 3, where it will be seen they encircle cylinder 15, the valves, as here shown, being of segmental form, four in number, abutting each other and forming a ring around the cylinder 15 and opposite ports 16 at their delivery end. To insure the seating ofthe valves 16, when not being subjected to interior pressure, they have formed on them lugs 20, to which are attached and seated springs 21, the outer and curved ends of the springs bearing against and within the outer wall 22 of chamber 17. Secured to the top of cylinder by bolts 23 is a cover or cap 24, having stiffening-ribs 25 and pierced by openings 26 through its top. 10 The cover or cap 24 extends down outside and clear of cylinder 15, where its lower edge terminates above valves 19, just freely clear of them to prevent binding, and prevent them from lifting, while openings 28 permit free fluid flowing from space 29 into chamber 17, after passing ports 19. Spring 11, mounted on valve 8, seats under cap 24 at its upper end and assists the gravity of valve 8 to seat it. A cover 30 is secured by bolts 31 to flange 2o 32 of wall 22.

In Fig. 5 I show a modification of the ports and checkvalves surrounding the pistonvalve. Ports 16 open through cylinder 15 outward, thence at an angle upward through an inclined seat 33, its lower and outer end 34 being formed circular, and valve 19 rests upon seat 33, and its lower edge 35 is formed to fit into and roll in seat 33, while spring 21 is secured to a lug 20 and its ends abut wall 22'.

In Figs. 1,2, and 6 I show my form of piston comprising a central part 36, attached to the piston-rod 37 and cylindrical in general form until nearing its top, where a shoulder 38 is formed, and rising therefrom is a coned part 39. The outer surface of part 36 has grooves 40 formed therein, the grooves being as deep as shoulder 38 at their top and somewhat deeper at the bottom end of part 36. Surrounding central part 36 is a shell 41 of nearly the interior diameter of barrel 1 and interiorly a free working fit over central part 36 .and at its top formed to fit snugly over coned part 39, to which it is ground to prevent any leakage. From shoulder 38 downward the shell 41 is longer than the central part 36, and a retaining-ring 42 is secured to shell 41 at its lowerend by screws 43, the ring 42 being wide enough to pass within the outer diameter of the central part 36, which seats upon it when the piston is descending, as seen in Fig. 2. Within the outer surface of shell 41 are grooves 44, within which are placed packing-rings 45, which snugly press to the cylinder 2 of barrel 1 and prevent any fluid passing between shell 41 and cylinder 2, and they also cause suflicient friction to hold shell 41 from moving in either direction, at either end of the stroke,until central part 36 is forced to ring 42, as in decending, or cone 39 is forced to its seat in the shell 41, as in ascending.

The operation of my mechanism is as follows:' When the piston 36, 39, &c., descends, as in Fig. 2, the movement downward draws part 36 of the piston down to ring 42, where it seats. This movement draws cone 39 away from the seat in shell 41 and allows an annular opening 46 to be formed, through which the fluid entering grooves 40 passes to the part of barrel or cylinder 1 above the gravity-piston. The piston-valve 8 during this time is held securely to its seat 7 by its own gravity, and the entering fluid is confined in barrel 1 between the piston 36 and piston-valve 8. As the crank which operates pistonrod 37 and the piston 36 passes its lower dead-center the slow movement at that time permits the central part 36 to assume the position in shell 41, as seen in Fig. 1, without shock or thumping, the shell being retarded at each change of movement by the friction of rings 45 in cylind er 2. With the upward and forcing movement of the piston the part 36 is forced up off of ring 42 and its cone 39 tightly seated in the coned part of shell 41. This upward movement overcomes the weight of the piston-valve 8 and the pressure of its spring 11. The piston-valve moves upward oif of its seat 7, ports 16 are uncovered, valves 19 are pressed outward, and the compressed fluid is delivered into chamber 17 and its delivery 18. Upon the return stroke of the piston valves 19 are forced by their springs 21 and ports 16 are closed. The piston-valve 8 passes to its seat 7 below the ports 16, thus making secure both ends of ports 16 against any leakage.

In my piston I have reduced the movable parts to a minimum, and thus greatly overcome the liability of parts becoming detached and falling into the barrehwhere, owing to the usual contracted clearance-space between piston and lower head, they are liable to do serious damage by breaking either the head or the cylinder.

I claim 1. In a pneumatic pump or compressor, a pump-barrel having an open end and thereto attached an enlarged cylinder, a piston-valve seated at the end of the barrel and within the cylinder, ports opening through the cylinder and above the piston-valve seat, a chamber exterior to the cylinder, and valves Within the chamber, surrounding the cylinder,adapt- ,ed to yield to pressure from within the cylinder and open the ports, and means to press the valves to their seats and close the ports upon the cessation of pressure from within the cylinder, substantially as set forth.

2. In a pneumatic pump or compressor, a pump-barrel having an open end and a valve seated thereon, ports opening outward from and above the valve-seat, an angled checkvalv'e seat at the outer end of the ports having its lower and outer end terminating in a curve, check-valves upon the angled seats, entering the curved end of the seat and guided therebyv for swinging movement, and means to force the valves to their seats, in manner and form substantially as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

DANIEL L. HOLDEN.

Witnesses:

R. O. WRIGHT, WILLIAM C. STOEVER. 

